V-groove ferrule mating sleeve

ABSTRACT

A ferrule sleeve includes a sleeve body, where the sleeve body is shaped in a V and includes a V-shaped groove that runs a length of a first side of the sleeve body. The ferrule sleeve further includes a sleeve cover, having a flat, rectangular shape, which fits into an opening of the V-shaped groove of the sleeve body. The ferrule sleeve further includes a cover spring that fits into the opening of the V-shaped groove of the sleeve body adjacent the spring cover, wherein the sleeve cover and the cover spring, when a first cylindrical ferrule is inserted within the V-shaped groove act to hold the first cylindrical ferrule within the V-shaped groove and prevent the first cylindrical ferrule from rotating, or from moving in a longitudinal.

BACKGROUND

Fiber connectors permit cables that contain optic fibers to be connected with one another via a separable interface that allows for easy disconnection and reconnection of the cables. When fiber connectors are mated with one another, the optic fibers in each cable should be aligned with one another to facilitate optical transmission between the optic fibers. To minimize losses associated with the mated fiber connectors, it is important that the fiber connectors provide accurate fiber alignment (i.e., core-to-core alignment of the fiber media) and that the ferrule end faces of each fiber connector be precisely shaped such that optimum physical contact can be maintained between each mated fiber pair.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are diagrams that illustrate a cylindrical ferrule sleeve used to mate ferrules associated with optic cables;

FIG. 2 is a diagram that depicts a three dimensional view of a ferrule sleeve according to a first exemplary embodiment;

FIG. 3A is a diagram that depicts a view of a face of the ferrule sleeve of FIG. 2;

FIG. 3B is a diagram that depicts a view along a length of the ferrule sleeve of FIG. 2;

FIGS. 4, 5, 6A, 6B and 6C are diagrams that depict placement of ferrules associated with optic cables into the ferrule sleeve of FIGS. 2, 3A and 3B;

FIGS. 7A, 7B and 7C are diagrams that depict views of a ferrule sleeve according to a second exemplary embodiment; and

FIGS. 8A and 8B are diagrams that depict placement of ferrules associated with optic cables into the ferrule sleeve of the embodiment of FIGS. 7A, 7B and 7C.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. The following detailed description does not limit the invention.

A ferrule sleeve, as described herein, acts as a mating sleeve between two cylindrical ferrules containing optic fibers to provide consistent optical connection performance and alignment of the optic fibers. The ferrule sleeve, according to a first embodiment, includes a V-shaped inner groove that receives fiber optic cable ferrules, and a sleeve cover and a cover spring that snaps into place over the V-shaped groove to retain the cable ferrules in a precise position with respect to one another such that the ferrules don't move in a longitudinal direction within the V-shaped groove, and don't rotate relative to one another. The V-shaped groove of the ferrule sleeve, in conjunction with the sleeve cover and the cover spring, maintains physical contact between end faces of the cable ferrules and maintains accurate optic fiber alignment.

The ferrule sleeve, according to a second embodiment, includes a cylindrical sleeve having key notches at each end of the sleeve that mate with keys located on the ferrules themselves, or located within housings associated with the ferrules and the attached cables that carry the optic fibers. The ferrule sleeve, according to this second embodiment, is formed from a flexible material with an inner diameter slightly smaller than the outer diameter such that the ferrule sleeve maintains a grip upon ferrules inserted within the ferrule sleeve. Upon insertion of the ferrules within the ferrule sleeve and mating of the key notches at each end of the ferrule sleeve with the corresponding keys, the ferrule sleeve is held in rotational position with respect to the ferrules to maintain optic fiber alignment.

FIG. 1A depicts a cylindrical ferrule mating sleeve 100 that can be used to mate ferrules 110 and 120 associated with two different fiber optic cables 130 and 140 that include optic fibers 150 and 160. Cylindrical ferrule mating sleeve 100 may, for example, be composed of a ceramic or a polymer (e.g., composite polymer) material. As further shown in FIG. 1B, during an installation process by a user, ferrule 110 is inserted into an open end of cylindrical ferrule mating sleeve 100, and ferrule 120 is inserted into another open end of mating sleeve 100. Ferrules 110 and 120 are inserted into mating sleeve 100 until the ferrule faces abut one another and thereby align optic fibers 150 and 160. In the configuration depicted in FIG. 1B, however, mating sleeve 110 may move around relative to ferrules 110 and 120, and ferrules 110 and 120 may slide within mating sleeve 110 relative to one another. Movement of mating sleeve 100 and/or ferrules 110 and 120 may negatively affect the alignment of fiber optics 150 and 160, thereby causing transmission losses (i.e., insertion losses).

FIGS. 2, 3A and 3B depict a ferrule sleeve 200 according to a first exemplary embodiment described herein. As shown in FIG. 2, ferrule sleeve 200 may include a sleeve body 210, having a V-shaped groove 220 disposed on an upper surface of sleeve body 210, a sleeve cover 230, and a cover spring 240. Sleeve body 210 may include a longitudinal member that has a V-shaped lower surface, and a V-shaped upper surface that serves as the V-shaped groove 220 which receives cylindrical ferrules of optical cable connectors (as described further below). V-shaped groove 220 may, as shown in FIG. 2, open outwards slightly at each end of ferrule sleeve 200 to more easily permit ferrules to be inserted into each end of V-shaped groove 220. Therefore, in the implementation shown in FIG. 2, a cross section of ferrule sleeve 200 taken towards each outer end of V-shaped groove 200 will have a larger V-shape than a cross section of ferrule sleeve 200 taken towards a middle of V-shaped groove 200. Though not depicted in FIG. 2, outer edges of the V-shaped upper surface of V-shaped groove 200 (i.e., edges disposed along each of the faces of ferrule sleeve 210) may be slightly rounded to facilitate ease of insertion of ferrules (not shown) into V-shaped groove 220.

Sleeve cover 230 may include a longitudinal member that has a flat, rectangular shape. Sleeve body 210 and sleeve cover 230 may be formed from a ceramic or polymer material. Sleeve body 210 and sleeve cover 230 may be formed from a same material, or from different materials. As shown in FIG. 2, sleeve cover 230 may be inserted into (and retained within) an opening of V-shaped groove 220 to place ferrule sleeve 200 in a closed configuration and firmly hold cylindrical ferrules (not shown) placed within V-shaped groove 220. A cover spring 240 may be inserted within retaining slots (not shown in FIG. 2) within the opening of V-shaped groove 220, adjacent to sleeve cover 230, to hold sleeve cover 230 in the closed configuration and to apply downwards force upon sleeve cover 230 so as to firmly hold the cylindrical ferrules (not shown) inserted within V-shaped groove 220. Cover spring 240 may include a metal material formed in a single flat plane in a shape that gives cover spring 240 spring-like properties when inserted into the opening of V-shaped groove 220. In some implementations, cover spring 240 may have a different shape than that shown in FIG. 2 as long as cover spring 240 functions to apply force to sleeve cover 230 within the upper opening of V-shaped groove 220.

FIG. 3A depicts a view of a face of ferrule sleeve 200, and FIG. 3B depicts a view along a length of ferrule sleeve 200. As shown in FIGS. 3A and 3B, sleeve body 210 of ferrule sleeve 200 may have a width of d₁, a height of d₂ and a length of d₃. V-shaped groove 220 of sleeve body 210 may have an opening width d₄ of the upper portion of V-shaped groove 220 and a depth of d₅ (i.e., to the bottom of the trough of V-shaped groove 220) at a mid-point along a length of ferrule sleeve 200. In an implementation in which V-shaped groove 220 opens slightly at each end of V-shaped groove 220 (as shown in FIG. 2, 3A and 3B), width d₄ and depth d₅ may be slightly larger at each outer end of V-shaped groove 220. As depicted in FIG. 3A, each lower surface of sleeve body 210 may have an angle θ relative to a plane that is perpendicular to a center-line plane that bisects V-shaped groove 220. Each lower surface of sleeve body 210 and the inner surface of V-shaped groove 220, thus, has an angle 90- θ relative to the center-line plane that bisects V-shaped groove 220. Sleeve body 210 has a thickness, from the lower surface of sleeve body 210 to the inner surface of V-shaped groove 220 (as measured from an upper surface of sleeve body 210), of d₆. As further shown in FIGS. 3A and 3B, sleeve cover 230 may have a width d₄ and a length d₃. Specific values for the dimensions d₁, d₂, d₃, d₄, d₅ and d₆ and angle θ may be selected to precisely fit an outer diameter and a length of the cylindrical ferrules that are to be inserted into V-shaped groove 220 of sleeve body 210 such that, when sleeve cover 230 and cover spring 240 are inserted into the opening of V-shaped groove 220, sleeve cover 230, cover spring 240 and V-shaped groove 220 hold the ferrules firmly so that they don't move in a lengthwise direction and don't rotate. Therefore, the specific values for the dimensions d₁, d₂, d₃, d₄, d₅ and d₆ and angle θ may vary depending on the size of the ferrules that are to be inserted into ferrule sleeve 200.

FIGS. 4, 5, 6A, 6B and 6C depict placement of ferrules associated with optic cables into ferrule sleeve 200. As shown in FIG. 4, prior to insertion of ferrules 400 and 410 into ferrule sleeve 210, sleeve cover 230 may be inserted (i.e., snapped into place) into retention slots (not shown) in an upper opening of V-shaped groove 220, and cover spring 240 may also be inserted into the retention slots (shown in FIGS. 6B and 6C) within the upper opening of V-shaped groove 220 against sleeve cover 230. Once sleeve cover 230 and cover spring 240 have been inserted into V-shaped groove 220 to close ferrule sleeve 200 (FIG. 5), ferrule 400 and ferrule 410 may be slid into each opposite end of V-shaped groove 220, as shown in FIG. 6A, until the end faces of ferrules 400 and 410 abut one another and are mated. Abutting the end faces of ferrules 400 and 410 creates an optical connection between the optical fibers running through ferrules 400 and 410 (not shown in FIG. 6A).

FIGS. 6A, 6B and 6C depict ferrules 400 and 410 completely slid into V-shaped groove 220, with sleeve cover 230 and cover spring 240 inserted into retention slots 600-1 and 600-2 (shown in FIGS. 6B and 6C) on each side of the upper opening of V-shaped groove 220. Insertion of cover spring 240 into retention slots 600-1 and 600-2 against an upper surface of sleeve cover 230 applies force onto sleeve cover 230 such that sleeve cover 230 is held firmly against an upper surface of ferrules 400 and 410 that are inserted into V-shaped groove 220 of ferrule sleeve 200. The force applied by cover spring 240 against sleeve cover 230 prevents lengthwise movement and rotation of ferrules 400 and 410. Prevention of movement and rotation of ferrules 400 and 410 maintains physical contact between the end faces of ferrules 400 and 410 and also maintains accurate alignment (i.e., core-to-core alignment) of the fiber running through ferrules 400 and 410.

FIGS. 7A, 7B and 7C are diagrams that depict views of a ferrule sleeve according to a second exemplary embodiment. The embodiment of FIGS. 7A, 7B and 7C includes a cylindrical ferrule sleeve 700 having key notches at each opposite end of ferrule sleeve 700 for engagement with corresponding keys disposed on ferrules to be inserted into ferrule sleeve 700, or disposed in a cable housing (not shown) associated with the optic fiber cable that are terminated by the ferrules to be inserted into ferrule sleeve 700. Ferrule sleeve 700 may be formed from a flexible, or semi-flexible, material, such as, for example, a ceramic or a polymer (e.g., composite polymer) material. Ferrules 710 and 720 may each have an outer diameter Di. Ferrule sleeve 700 may have a cut 730 that extends lengthwise across an entire length of ferrule sleeve 700 and may have an inner diameter of D₁−Δ (i.e., where Δ is a small value such that the inner diameter of ferrule sleeve 700 is slightly smaller than the outer diameter D₁ of ferrules 710 and 720). Cut 730 permits ferrule sleeve 700 to “flex” slightly outwards and/or inwards such that, with inner diameter of ferrule sleeve 700 being slightly smaller than the outer diameter of ferrules 710 and 720, insertion of ferrules 710 and 720 within ferrule sleeve 700 causes ferrule sleeve 700 to “grip” the outer surfaces of ferrules 710 and 720.

Ferrule sleeve 700 may further include key notches 740-1 and 740-2 disposed at each end of ferrule sleeve 700. As shown in the implementation depicted in FIGS. 7A, 7B and 7C, key notches 740-1 and 740-2 may include triangular shaped key notches. In other implementations, other shapes (e.g., rectangular key notches) may alternatively be used. Key notches 740-1 and 740-2 may have a size and shape that match corresponding keys 750-1 and 750-2 disposed on the outer surfaces of ferrules 710 and 720 (as depicted in FIGS. 7A - 7C), or disposed in cable housings (not shown) associated with each of the optic fiber cables 760 and 770 that are terminated by ferrules 710 and 720.

FIGS. 8A and 8B are diagrams that depict placement of ferrules associated with optic cables into the ferrule sleeve of the embodiment of FIGS. 7A, 7B and 7C. As shown, ferrule 710 may be slid into one end of ferrule sleeve 700, and ferrule 720 may be slid into an opposite end of ferrule sleeve 700. End faces of each of ferrules 710 and 720 may abut one another when key 750-1 mates with key notch 740-1 and key 750-2 mates with key notch 740-2. The mating of key 750-1 with key notch 740-1 and key 750-2 with key notch 740-2 holds ferrules 710 and 720 in place such that ferrules 710 and 720 cannot rotate with respect to one another. Additionally, the flexing of ferrule sleeve 700, with the inner diameter of ferrule sleeve 700 being slightly smaller than the outer diameter of ferrules 710 and 720, enables ferrule sleeve 700 to grip the outer surfaces of ferrules 710 and 720, thereby inhibiting lengthwise movement of ferrules 710 and 720 within ferrule sleeve 700. Prevention of lengthwise movement, and rotation, of ferrules 710 and 720 maintains physical contact between the end faces of ferrules 710 and 720 and also maintains accurate alignment (i.e., core-to-core alignment) of the fibers running through ferrules 710 and 720.

The foregoing description of implementations provides illustration and description, but is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. No element used in the description of the present application should be construed as critical or essential to the invention unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise.

In the preceding specification, various preferred embodiments have been described with reference to the accompanying drawings. It will, however, be evident that various modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope of the invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense. 

What is claimed is:
 1. A ferrule sleeve, comprising: a first longitudinal member having a V-shaped groove that runs a length of the first longitudinal member, wherein the V-shaped groove receives cylindrical ferrules; and a second longitudinal member that fits within the V-shaped groove as a cover of the V-shaped groove, wherein the second longitudinal member has a flat, rectangular shape that fits into an upper portion of the V-shaped groove.
 2. The ferrule sleeve of claim 1, further comprising: a spring that fits within the V-shaped groove against the second longitudinal member.
 3. The ferrule sleeve of claim 1, wherein the first longitudinal member and the second longitudinal member comprise a polymer or ceramic material.
 4. The ferrule sleeve of claim 1, wherein the V-shaped groove is disposed on an upper surface of the first longitudinal member and wherein a lower surface of the first longitudinal member is V-shaped.
 5. The ferrule sleeve of claim 1, wherein the second longitudinal member snaps into retention slots in the upper portion of the V-shaped groove to cover the V-shaped groove.
 6. The ferrule sleeve of claim 1, further comprising: retention slots, formed within a first upper portion and a second upper portion of the V-shaped groove, into which the second longitudinal member is inserted to cover the V-shaped groove.
 7. The ferrule sleeve of claim 2, wherein, when a first cylindrical ferrule of the cylindrical ferrules is inserted within the V-shaped groove, the second longitudinal member and the spring, when inserted into the upper portion of the V-shaped groove, act to hold the first cylindrical ferrule in place, preventing the first cylindrical ferrule from moving or rotating.
 8. The ferrule sleeve of claim 7, wherein, when a second cylindrical ferrule of the cylindrical ferrules is placed within the V-shaped groove, the second longitudinal member and the spring, when inserted into the upper portion of the V-shaped groove, act to hold the first and second cylindrical ferrules in place so as to prevent the first cylindrical ferrule and the second cylindrical ferrule from rotating, or from moving in a longitudinal direction, with respect to one another.
 9. The ferrule sleeve of claim 1, wherein the ferrule sleeve comprises a mating sleeve for mating optic fibers contained within the cylindrical ferrules.
 10. The ferrule sleeve of claim 1, wherein the cylindrical ferrules connect to cables that carry one or more optic fibers.
 11. A method, comprising: obtaining a first longitudinal member having a V-shaped groove that runs a length of the first longitudinal member; inserting a second member, that comprises a flat, rectangular shape, into an upper portion of the V-shaped groove such that the second member acts as a cover over the V-shaped groove; inserting a spring into the upper portion of the V-shaped groove to apply force against the second member; inserting a first cylindrical ferrule length-wise in the V-shaped groove at a first end of the first longitudinal member; and inserting a second cylindrical ferrule length-wise in the V-shaped groove at a second end of the first longitudinal member such that a first end of the first cylindrical ferrule substantially touches a first end of the second cylindrical ferrule.
 12. The method of claim 11, wherein the V-shaped groove is disposed on an upper surface of the first longitudinal member and wherein a lower surface of the first longitudinal member is V-shaped.
 13. The method of claim 11, wherein the first cylindrical ferrule contains a first optic fiber and wherein the second cylindrical ferrule contains a second optic fiber.
 14. The method of claim 11, wherein inserting the second member and the spring comprises: snapping the second member and the spring into retention slots in the upper portion of the V-shaped groove to hold the first cylindrical ferrule and the second cylindrical ferrule in place within the V-shaped groove.
 15. A ferrule sleeve, comprising: a sleeve body, wherein the sleeve body is shaped in a V and includes a V-shaped groove that runs a length of a first side of the sleeve body; and a sleeve cover, having a flat, rectangular shape, that fits into an opening of the V-shaped groove of the sleeve body, a cover spring that fits into the opening of the V-shaped groove of the sleeve body adjacent the spring cover, wherein the sleeve cover and the cover spring, when a first cylindrical ferrule is inserted within the V-shaped groove act to hold the first cylindrical ferrule within the V-shaped groove and prevent the first cylindrical ferrule from rotating, or from moving in a longitudinal direction.
 16. The ferrule sleeve of claim 15, wherein the sleeve cover and the cover spring, when a second cylindrical ferrule is inserted within the V-shaped groove adjacent the first cylindrical ferrule act to hold the first cylindrical ferrule and the second cylindrical ferrule and prevent the first cylindrical ferrule and the second cylindrical ferrule from rotating, or from moving in a longitudinal direction, with respect to one another.
 17. The ferrule sleeve of claim 16, wherein the ferrule sleeve comprises a mating sleeve for mating optic fibers contained within the first and second cylindrical ferrules.
 18. The ferrule sleeve of claim 15, wherein the sleeve body extends a length in a longitudinal direction sufficient to fit a portion of the first cylindrical ferrule and a portion of the second cylindrical ferrule within the V-shaped groove.
 19. The ferrule sleeve of claim 15, further comprising: retention slots, formed within a first upper portion and a second upper portion of the V-shaped groove, into which the sleeve cover and the spring cover are inserted.
 20. The ferrule sleeve of claim 15, wherein the first cylindrical ferrule connects to a cable that carries one or more optic fibers. 